81670032 has 200 divisors, whose sum is σ = 255218040. Its totient is φ = 25159680.

The previous prime is 81670031. The next prime is 81670051. The reversal of 81670032 is 23007618.

It can be written as a sum of positive squares in 4 ways, for example, as 4511376 + 77158656 = 2124^2 + 8784^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 81669978 and 81670005.

It is not an unprimeable number, because it can be changed into a prime (81670031) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1540918 + ... + 1540970.

Almost surely, 2^81670032 is an apocalyptic number.

81670032 is a gapful number since it is divisible by the number (82) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81670032, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (127609020).

81670032 is an abundant number, since it is smaller than the sum of its proper divisors (173548008).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81670032 is a wasteful number, since it uses less digits than its factorization.

81670032 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143 (or 128 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 81670032 is about 9037.1473375175. The cubic root of 81670032 is about 433.8646253932.

The spelling of 81670032 in words is "eighty-one million, six hundred seventy thousand, thirty-two".